Query Panel Bind Variable Value Can be getting using a below process

        DCBindingContainer bindings;
                bindings = (DCBindingContainer)BindingContext.getCurrent().getCurrentBindingsEntry();
                DCIteratorBinding dcIteratorBindings =
                    bindings.findIteratorBinding("IteratorName");
           date = "" + (dcIteratorBindings.getViewObject().getNamedWhereClauseParam("Bindingparametername"));